Why White Granite Has A Smaller Grain Size Than Rhyolite

The difference is the size of grains.

Why white granite has a smaller grain size than rhyolite.

Appearance of granite is veined or pebbled and that of rhyolite is banded. Occasionally it is light gray. Rhyolite and granite have the same chemical composition and are formed from the same type of liquid rock. Rhyolite is an extrusive igneous rock a felsic silica rich volcanic rock that includes obsidian and pumice.

Here is the actual problem that my homework says. The rapid cooling only allows small crystals to form. It has a composition similar to granite but has a much smaller grain size. Natural glasses like obsidian rhyolite glass cool so quickly that mineral grains do not have time to grow.

Why is the grain size of rhyolite less than 1mm while the grain size of granite is greater. Since granite cools underground from magma largecrystals form because the magmahas a chance to cool slowly. In texture it is classified as aphanitic. Granite is available in black grey orange pink white colors whereas rhyolite is available in grey white light black colors.

Occasionally it is light gray. The rapid cooling only allows small crystals to form. When we have to compare granite vs rhyolite the texture color and appearance plays an important role in determining the type of rock. Why does rhyolite have smaller crystals than granite.

Rhyolite has a composition similar to granite but has a much smaller grain size. The longer it takes to cool the larger the grain. This doesn t allow a lot of time for crystals to grow in the rock. It is composed of the light colored silicates and is usually buff to pink in color.

Smaller than granite i think you can change the grain size of a metal by heating it up to its melting point and then allowing it to cool again. It frequently contains voids and glassy fragments evidence of having formed in a surface environment with. It is composed of the light colored silicates and is usually buff to pink in color. Slow cooling allows for a longer period of grain growth and a high water content in the magma favors higher in melt transport rates and more rapid grain growth than would occur in a dry magma of equivalent composition and temperature.

Rhyolite which cools at the surface cools much more quickly than granite which cools underground. Ok i have this science homework that wasn t assigned at all until last minute notice so its mostly about comparing the two types of minerals. Rhyolite is the felsic igneous rock with fine grained size.